Piston mold



R. E. DAY

June 14, 1938.

PISTON MOLD Filed Ndv. 13, 1935 I. 4 mmmw u INVENTOR Patented June 14, 1938 UNITED STATES PATENT OFFICE PISTON MOLD Ray E. Day, Grosse Pointe Farms, Mich.

Application November 13, 1935, Serial No. 49,495 6 Claims. (01. 22-151) This invention relates to molds for casting pistons for internal combustion engines, such for example as aluminum alloy pistons, the invention being applicable in connection with split molds wherein either a sand core or a sectional steel core is utilized.

The present application is a continuation in part of my co-pending applications Serial Nos. 692,751 and 692,753 both filed on October 9,1933.

An object of the invention is to provide a mold for casting a piston having a head, piston pin bosses and oppositely spaced skirt or bearing faces, and wherein improved means is provided for casting into the piston struts or webs which 3 extend angularly and converge from the bosses to the skirt.

Another object of the invention is to provide a mold for casting a piston of the foregoing type in which the improved construction is such that the strut forming mold portions are separate from the core, thus providing a mold of relatively simplified construction adapted to permit more economical casting operations, and effect other desirable and beneficial results.

25 Another object is to provide improved means for clamping the mold sections together and for breaking the sections apart after the casting operation.

Other objects of my invention will appear from 30 the following description and appended claims when considered in connection with the accompanying drawing forming a part of this specification.

In said drawing:

35 Fig. 1 is a horizontal section, partly in plan, of one form of mold made in accordance with my invention.

Fig. 2 is a vertical section taken substantially along the line 2-2 of Fig. 1.

40 Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawing, since the inven- 45 tion is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is not 50 intended to limit the invention claimed herein beyond the requirements of the prior art.

Referring particularly to Figs. 1 and 2 of the drawing, the split mold is shown as a whole at In and comprises two similarly formed main mold 55 sections or halves II and I2 which are substantially semi-cylindrical. The mold sections are preferably provided on one side with projecting portions l3 which are pivotally connected together by means of a pintle or bolt M. The sections are provided also with projecting portions which, when the sections are in closed position provide a filler passage l6 which communicates with an upright feeder passage ll, formed by providing cooperating vertically extending semi-cylindrical recesses 18 in the abutting faces 10 of the mold sections.

The split mold sections II and I2, when closed, form a central core cavity within which is located a core C. This core may be of suitable material, and in the present instance, by way of example, is described as a sand core. Into this cavity, in the space between the core and each mold section wall at points at opposite sides of the central vertical plane normal to the vertical plane coincident with the line of split of the sections, there are insertable supplementary mold members which cooperate with the mold sections and core to form portions of the piston slippers, bosses and the diverging intermediate connecting struts.

Each mold section is provided with upper and lower extensions or projecting portions 19 which are vertically spaced apart and between which strut forming members 20 are positioned. These members 20 are mounted for horizontal swinging movement between the projections I9 by means of pintles or bolts 2 I. The walls of the mold sections are provided with cut-out portions and openings 22 into the core cavity through which the feet or free end portions 200. of the members 20 extend. Similar openings are formed in each of the mold sections. The surrounding walls of the openings 22 are formed to provide guide means for the members 20 and serve to direct said members into their proper positions within the mold cavity. The walls of the sections between the openings 22 are provided with radial holes 23 through which removable pins 24 are inserted to form the wrist pin openings in the piston bosses. By providing the curved ends 20a, which cooperate with the correspondingly curved surfaces of the core and with the mold sections the finished piston is formed with strut members, herein shown as curved, which connect the skirt with the piston pin bosses.

Referring particularly to Fig. 2 it will be noted that the mold sections are provided with inwardly extending flanges or portions 25, these being for the purpose of locating in proper position a sand core shown at C which is supported between the bottom ledges of the mold sections and said locaters 25.

When it is desired to cast a piston in the mold, the core C is placed in properly located position within one of the split sections. The mold sections H and I2 are then closed by relatively swinging them about the pintle l4, assuming the position shown in Fig. l. The supplementary mold members 20 are then swung into their full line positions so as to project into the core cavity between and spaced from the core C and the adjacent walls of the mold sections. When the core is in position it will be noted that a space is provided between the ends 20a of the strut forming members and the adjacent faces of the core and mold sections, and that other spaces are provided between the core and the mold sections and its parts to form the finished casting. Molten metal is then poured into the passage l6, flows upwardly through the passage I! and out through the feeder slot 26 into the interior of the mold sections, filling the spaces surrounding the core. After the metal has cooled and set, the members 28 are swung outwardly about their pintles 2|, the pins 24 are removed and the mold sections are separated, whereupon the molded casting and the core may be removed.

I claim:

1. A split mold for casting pistons, comprising a pair of cooperating hinged together mold sections forming a core cavity to hold a core therein, each section having a pair of openings into the core cavity located at opposite sides of the center of its wall, and a pair of supplementary mold members for each mold section and having offset free end portions shiftable through said openings into the core cavity between the core and the walls of the sections.

2. A split mold for casting pistons, comprising a pair of cooperating mold sections forming a core cavity to hold a core therein, each section having a pair of openings into the core cavity located at opposite sides of the center of its wall, and a pair of supplementary mold members for each of said mold sections having offset free end portions shiftable through said openings into the core cavity between the core and the walls of the sections and spaced therefrom.

3. A split mold for casting pistons, comprising a pair of cooperating hinged together mold sections forming when closed a central core cavity, a core insertable in said cavity, the wall of each section having openings into the cavity, spaced projections carried by each of said mold sections, and removable swinging supplementary mold members carried by said projections and having oifset free end portions insertable through said openings into and out of position within said core cavity.

4. A split mold for casting pistons, comprising a pair of cooperating hinged together mold sections forming when closed a central core cavity, a core insertable in said cavity, the wall of each section having openings into the cavity, a pair of substantially parallel spaced projections carried by each of, said mold sections, and an independent removable supplementary mold member pivotally mounted'between each pair of projections and having a laterally extending free end insertable through one of said openings into the core cavity.

5. A split mold for casting pistons, comprising a pair of cooperating hinged together mold sections forming when closed a central core cavity, a core insertable in said cavity, the wall of each section having openings into the cavity, each of said mold sections having at least one pair of substantially parallel spaced projections, a pintle connecting the free ends of each pair of projections, and a supplementary mold member mounted for swinging movement upon each of said pintles and having an offset free end portion insertable through one of said openings into the core cavity.

6. A split mold for casting pistons, comprising a pair of cooperating hinged together mold sections forming when closed a central core cavity, a core insertable in said cavity, the wall of each section having openings into the cavity, vertically spaced pairs of projections carried by each of said mold sections, and a supplementary mold member having one end thereof pivotally mounted between each pair of projections and an offset free end insertable through one of said openings into said core cavity.

RAY E. DAY. 

